Starter gearing for internal combustion engines



Oct. 26, 1943. T. B. MARTIN 2,

STARTER GEARING FOR INTERNAL COMBUSTION ENGINES I Filed March 4, 1941 2Sheets-Sheet 1 7 1 jg 15 68 z 19 17 INVENTOR.

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T. B. MARTIN Oct. 26, 1943.

I STARTER GEARING FOR INTERNAL COMBUSTION ENGINES Filed March 4, 1941 2Sheets-Sheet 2 INVENTOR. homasfi. JTLaW/tin/ ATTORNEY.

Patented Oct. 26, 1943 UNITED STAT I 2,332,864; Fl CE STARTER GEARINGFOR INTERNAL -COMBUSTION ENGINES Thomas B. Martin, Dayton,0hio, assignorto Benclix Aviation Corporation, South Bend, Ind., a

corporation of Delaware Application March 4, 1941, Serial No. 381,688

13 Claims.

The present invention relates to starter gearing for internal combustionengines and more particularly to that type in which a motordriven pinionis shifted manually or by other extraneous means into and out ofengagement with a member of an engine to be started.

In installations of this character it is desirable to connect the pinionto the starting motor through some form of overrunning clutch device inorder to permit the engine member to accelerate when the engine becomesself-operative with.- out accelerating the armature of the startingmotor to a dangerous or harmful speed of rotation. Considerabledifficulty has been encountered in constructing an overrunnin clutch forthis purpose which will on the one hand transmit the cranking torque atall times without slippage, and on the other hand will release andoverrun without sticking.

It is an object of the present invention to provide a novel starter gearshift which is efficient and reliable in operation and simple andeconomical in construction.

It is another object to provide such a device which is arranged tocouple the pinion to its drive shaft positively and with small lostmotion .upon the actuation of said shaft. i

It is a further object to provide such a device in which the couplingaction may be cushioned if deemed desirable without rendering the actionanyless positive and certain.

It is another object to provide such a device in which the coupling isarranged to overrun freely when the engine becomes self-operativewithout causing undue acceleration of the drive shaft.

It is another object toprovide such a device in which localized stressesare avoided, and the torque is transmitted by pressures on comparativelylarge surfaces which are arranged at a considerable angle to thedirection of the force transmitted.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawings in Which:

Fig. 1 is a side elevation partly in section of a preferred embodimentof the invention;

Fig. 2 is a section taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a section taken substantially on the line 3-3 of Fig. 1;

Fig. 4 is a view similar to Fig. 1 showing a second embodiment of theinvention;

Fig. 5 is a section taken substantially on the line 5-5 of Fig. 4;

Fig. 6 is a view similar to Fig. 1 of a third embodiment of theinvention;

Fig. 7 is a section taken substantially on the line .ll of Fig. 6;

Fig. 8 is a view similar to Fig. 6 showing the parts in operative ordriving position;

Fig. 9 is a view similar to Fig. 4 showing the control nut fixedlyattached to the drive sleeve instead of being frictionally clutchedthereto, and showing the pinion bushing formed to act as a detent forthe screw shaft;

Fig. 10 is a section taken substantially on the line Ill-I0 of Fig. 9;and

Fig. 11 is a detail in side elevation of the pinion with its clutchmember and frictional mounting for the screw shaft illustrated in Fig.9,

In Fig. l of the drawings there is illustrated a power shaft I having adrive sleeve 2 splined thereon. A pinion member 3 is slidably journalledon the power shaft and connected for longitudie nal movement with thedrive sleeve by means of a barrel member 4 fixedly attached to thepinion as indicated at 5 and swiveled to the end of the sleeve 2 bymeans of a radial flange 6 on the end of the sleeve which is confinedbetween split thrust rings I and 8 mounted in the interior of thebarrel.

An overrunning torque transmitting connection between the sleeve andpinion is provided comprising a screw shaft 9 slidably journalled on thepower shaft inside the barrel 4 and having clutch teeth II on one endthereof. A, toothed clutch member I2 is rigidly mounted in the end ofthe sleeve 2 in any suitable manner as by Welding or brazing in positionto be engaged by the clutch teeth I I of the screw shaft 9 when thescrew shaft moves tothe right in Fig. 1. A nut I3 is threaded on thescrew shaft 9 within the barrel 4 and is maintained in frictionalengagement with a washer I4 at the inner end of the barrel by springmeans such as a dished spring washer i5 engaging an annular projectionIS on the nut and seated against the split thrust ring 1 in the barrel.

Means for shifting the sleeve 2 with the pinion and barrellongitudinally on the power shaft I to move the pinion into and out ofengage ment with an engine member, is provided in the formof a shiftcollar ll slidably mounted on the periphery of the sleeve 2 andyieldably held against a split thrust ring Iii by a'compression springI9 bearing against the flange 8 of the sleeve.

Means for frictionally connecting the screw shaft 9 to the power shaft Iis provided in the.

form of a spring clutch ring'fii (Fig. 3) anchored to the screw shaft atone end as by means of an outturned terminal portion 122 located in aradial bore 23 in the screw shaft, and wound around the power shaft inoadirection to cause the clutch ring to grip the shaft'when the shaftrotates in a forward direction as indicated by the arrow in Fig. 3. p

In the operation of this embodiment of the invention, after the pinion 3has been moved into engagement with an engine gear, rotation of thepower shaft I by a starting motor, not illustrated, will cause rotationof the. sleeve Z by virtue of tionary by its frictional connectionthrough the washer l4 and the spring washer i5 with the pinion barrel 4,the screw shaft 9' will be caused to move to the right in Fig. 1 untilthe clutch H, 12 is closed. Thereafter, the screw shaft is positivelyrotated through said clutch from the power shaft I, and the nut I3 isforced against the washer l4 by the screw jack action between the screwshaft and nut whereby the pinion 3 is constrained to turn with thesleeve 2 and consequently with the powershaft I. When the enginestartsthe overrunning of the pinion causes the screw shaft to bethreaded to the left in Fig. 1, causing it to be declutched from thesleeve and power shaft whereby the pinion, barrel, nut and screw shaftoverrun freely until the assembly is returned to idle position by theoperator. In the embodiment of the invention illustrated in Figs. 4 and5 a powershaft 3! has splined thereon a sleeve 32, and a pinion 33 isslidably journalled on a bushing 34 freely mounted on the power shaftand extending into the end of the sleeve 32.

Sleeve 32 is provided with an enlarged bell 35 fixed to the sleeve inany suitable way as by welding or brazingas indicated at 36 and having aswiveled connection with the pinion 33 as by means of a flange 3'l fixed in any suitable way to the pinion and confined in the end of thebell bymeans of a Washer 38 located by a split lock ring 39. I J t Theinner end of the pinion 33 is formed as a dental clutch 4!, and a screwshaft #32 is slidably journalled on the bushingi l and provided withclutch teeth 43 adapted to cooperate with the clutch 4|. Means foryieldingly urging the screw shaft in a direction to close the clutch isprovided in the form of a return spring bearing against the screw shaftat one end and at its other end against a Washer 45 retained by a flange46,0n theend of the bushing 3 I A nut 41 is threaded on the screw'shaa42 and is provided with afco nic'al periphery 48 bearing against aninner conical surface 49 of the bell 35 so as to form a friction clutch,connection therewith. Means for yieldingly holding these surfaces "incontact is provided in the form of a spring washer 5! bearing against anannular projection 52 on the nut and seated against a split thrust ring53 in the bell 35. l

Means for shifting the sleeve 32 along the power shaft l in'order tocause the pinion 33 to engage an engine member, is provided in the formof a collar 54 slidably mounted on the sleeve '32 and maintained thereonby a split thrust ring 55 against the pressure or a spring 58 bearingagainst the end of the bell 35.

the shift collar 54 is actuated by'any When conventional type of shiftfork to move the pinion into operative. position, power shaft 3i will berotated by a starting motor, which rotation is thereupon transmittedthrough the splines to the sleeve "32 and bell 35, thus causing rotationof [the mm 4'! through its frictional connection with the bell 35. Thescrew jack action between the nut and screw shaft thereupon causes thescrew shaft to move to the left, closing clutch 41,43, after which thenut i'l is forced againstthe interior of the bell 35 so as to form adriving connecaonnom the bell "through the nut and screw the pinion.When the engine starts, the

overrunnin'g'of'the pini on'causes'the screw shaft thereto in anysuitable way as indicated at 65.

A bell 66 is suitably fixed on the end of the sleeve 6'2 surrounding thenut es and ha a ring at of elastically deformable material mountedtherein. Ring 6'5 is held under initial compression by means of athimble 6S surrounding the nut 64 and seated against a shoulder 65 inhell E6, and a thrust ring H bearing against a split lock ring 12 in theopen end of the bell. Nut ii is provided with a radial flange E3 in thebell 65 adjacent the thimble 58 whereby the nut and consequently thepinion are swiveled to the bell and sleeve 62. V

A screw shaft '54 is slidably jour'nalled on the power shaft and isprovided at one end with a clutch formation is adapted to engage aclutch member 16 fixed in the end of sleeve 52. Selftightening meansfrictionally connecting the screw shaft to th power shaft fiiis providedin the form of a clutch ring 'i'! (Fig. 7) anchored to the screw shaftby an outturned end '58 lodged in a radial bore 'EQ of. the screw shaftand wound around the power shaft in a direction to frictionally grip itwhen it turns in a forward direction as indicated by the arrow.

A shifting thinible ti is'slidably mounted on the sleeve 62, retainedthereon by a split lock ring $2 and having a yieldin thrust connectionwith the sleeve through. a compression spring 83.

When the shift collar Si is actuated by any conventional form ofshifting fork to rnove the pinion into engagement with an engine geasuch as indicated at 84 in Fig. 8, rotation of the power shaft Si istransmitted to the sleeve 62 through its splined connection therewithand is transmitted to the screw shaft M by the friction clutch ring Tl.Since the nut 5c is held stationary by its connection with the pinionas, the screw shaft T4 is caused to move to the right, closing clutch15, T6. Thereafter the nut as is caused to move to the left,eompressingthe lastic ring 6'! until sufficient torque is built up tocause rotation to be transmitted to the pinion and engine gear.

When the engine starts, the overrunning of the pi'nio'nfifi causes thescrew shaft 14 todeclutch, whereupon the pinion, nut and screw shaftoverrun until the pinion is moved back to idle position by the shiftingmeans.

The structure illustrated in Figs. 9, 10 and 11 i similar to that shownin Figs. 4 5 and the parts are similarly numbered, but in this case thenut and bell are formed integrally and designated by the numeral 56, thepinion flange is formed as the clutch member and is numbered All, andthe screw shaftdZ is 'frictionally connected to the pinion by cutting aspiral'groove 3D in the projecting end of the pinion bushing 35a wherebythe bushing acts as a self-expanding clutch within the screw shaft.,"The operation of this structure is substantially the same as thatillustrated in Figs. 4 and 5 except that the connection to the pinion ismore positive, and the traversal of the screw shaft isffacilitated byreason of the fact that the spir lly cut end of the bushing 36a. islongitudinally compressible so that while the bushing retards rotationof'the screw shaft, it does not materially impedefits longitudinalmovement;

have been shown and described in detail, it will be understood thatother embodiments are possible and various changes may be made in theconstruction and arrangement of the parts without departing from thespirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In a starter gear, a power shaft, a sleeve member slidably butnon-rotatably mounted thereon, a pinion member slidably journalled onthe shaft and connected for longitudinal movement with the sleeve, andan overrunning torque transmitting connection between the sleeve memberand pinion member including a threaded ring slidably and rotatablymounted on the power shaft having clutch teeth on one end, a nutthreaded thereon having a torque transmitting connection with one ofsaid members; and clutch teeth rigid with the other said member andadapted to cooperate with the clutch teeth of the ring and form a torquetransmitting connection therebetween.

2. In a starter gear, a power shaft, a sleeve member slidably butnon-rotatably mounted thereon, a pinion member slidably journalled onthe shaft and connected for longitudinal movement with the sleeve, andan overrunning torque transmitting connection between the sleeve meniberand pinion member including a threaded ring slidably and rotatablymounted on the power shaft independent from said sleeve having clutchteeth on one end, a nut threaded thereon having a torque transmittin andthrust connection with one of said members, and a toothed clutch memberrigid with the other said member and adapted to cooperate with theclutch teeth of the ring and form a torque transmitting connectiontherebetween when said teeth are forced into engagement by the screwjack action of the ring and nut. I v 3. In a starter gear, a powershaft, a sleeve member slidably but non-rotatably mounted thereon, apinion member slidably journalled on the shaft and connected forlongitudinal movement with the sleeve, and an overrunning torquetransmitting connection between the sleeve memberand pinion memberincluding a threaded ring slidably and rotatably mounted on the powershaft, a nut threaded thereon having, a torque transmitting connectionwith one of said members, a frictional connection between the ring andthe other of said members, and a positive torque transmitting connectionto the ring established by the screw jack action of thering and nut.

4. Starter gearing as set forth in claim 1 in which means are providedfor cushioning the establishment of the driving connection between thesleeve and pinion.

5. Starter gearing as set forth in claim 1 incorporating aself-tightening frictional connection between the sleeve and nut.

6. Starter gearing as set forth in claim 1 incorporating a block ofelastically deformable material interposed between the sleeve and nutand arranged to be compressed by the action of the threaded ring and nutto yieldably connect the sleeve to the nut for rotation in unison,

7. In an engine starter gear, a power shaft, a pinion slidablyjournalled thereon, and means for connectin the pinion to rotate withthe shaft including a sleeve non-rotatably mounted on the connectionbetween the screw shaft and pinion established by screw jack actionbetween the ring and nut.

8. In an engine starter, a power shaft, a pinion slidably journalledthereon, a sleeve splined to the shaft and having a swiveled connectionwith the pinion, means for, shifting the sleeve along the shaft, athreaded ring .rotatably and slidably mounted on the power shaft havinga clutch member at one end, a nut threaded on the ring, and meansincluding a member cooperating with the clutch member on the ring totransmit rotation throughthe ring and nut from the sleeve to the pinion.

9. In an engine starter, a power shaft, a pinion slidably journ'alledthereon, sleeve splined to the shaft and having a swiveled connectionwith the pinion, means for shifting the sleeve along the shaft, athreaded ring rotatably and slidably mounted on the power shaft,a nutthreaded on the ring having a torque-transmitting connection with thepinion, and means including a clutch closed by the screw jack action ofthe ring and nut for transmitting rotation from the sleeve to thepinion.

10. In an engine starter, a power shaft, a pinion slidably journalledthereon, a sleeve splined to the shaft and having a swiveled connectionwith the pinion, means for shifting the sleeve along the shaft, athreaded ring rotat'ably and slidably mounted on the power shaft havinga clutch member formed on one end, a nut threaded on the ring having atorque transmitting connection with the pinion, and a clutch memberrigid with the sleeve cooperating with the clutch member on the ring totransmit torque from the sleeve through the ring and nut to the pinion.

11. In an engine starter, a power shaft, a pinion slidably journalledthereon, a sleeve splined to the shaft and having a swiveled connectionwith the pinion, means for shifting the sleeve along the shaft, athreaded ring rotatably and slidably mounted on the power shaft having aclutch member formed on one end, a nut threaded on the ring having atorque transmitting connection with the sleeve, and a clutch memberrigidwith the shaft, a nut fixed to the sleeve and swiveled to pinioncooperating with the clutch member on the ring under the screw jackaction of the ring and nut to transmit torque from the sleeve throughthe ring and nut to the pinion.

12. In engine starter, a power shaft, a threaded ring slidablyjournalled on the power shaft and frictionally connected to rotatetherewith, a sleeve splined to the power shaft, a pinion slidablyjournalled on the power shaft and swiveled to the sleeve, a barrel fixedto the pinion, a nut threaded on the ring within the barrel andfrictionally connected to the barrel, and clutch means closed by thescrew jack action of the ring and nut for transmitting torque throughthe ring .threaded on the ring, means for moving the sleeve, nut andpinion along the shaft in unison to mesh the pinion with an enginemember, and means including a clutch closed by longitudinal movement ofthe ring in the nut to transmit rotation from the sleeve to the pinion.

THOMAS B. MARTIN.

